1. Field of the Invention
The present invention relates to a magnetic recording medium having a servo pattern formed of a concave/convex pattern in a servo patterns region, to a recording/reproducing apparatus having the magnetic recording medium, and to a stamper for manufacturing the magnetic recording medium.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. H09-97419 discloses a magnetic recording apparatus, which is composed of a discrete track type magnetic disk, as a recording/reproducing apparatus provided with this type of the magnetic recording medium. In this case, the magnetic disk mounted on the magnetic recording apparatus is arranged such that concentric recording tracks (band-shaped convex portions) composed of a magnetic recording member (magnetic material) is formed on one surface side of a glass disk substrate (base member) so that the magnetic disk can record and reproduce various types of data. Further, a guard band member (non-magnetic material) is filled in the concave portions between the recording tracks and forms guard band portions to improve the surface smoothness of the magnetic disk as well as to magnetically separate adjacent magnetic tracks from each other.
When the magnetic disk is manufactured, first, a magnetic recording layer is formed by sputtering a magnetic material on one surface side of a base member. Next, after a positive-type resist is spin coated and prebaked so as to cover the magnetic recording layer, a pattern similar to the pattern of the guard band portions is drawn using a mastering apparatus and subjected to development processing. With this operation, a resist pattern (concave/convex pattern) is formed on the magnetic recording layer. Subsequently, after the magnetic recording layer is etched using the resist pattern as a mask, a residual mask on the magnetic recording layer is removed by an ashing apparatus. With this operation, recording tracks composed of the magnetic material and a servo pattern (concave/convex pattern) is formed on the base member. Next, a non-magnetic material is sputtered to the base member in this state. At the time, the non-magnetic material is sputtered to a sufficient thickness until the concave portions constituting the servo pattern and the concave portions between the recording tracks are entirely filled with the non-magnetic material as well as the convex portions constituting the servo pattern and the recording tracks are covered with the non-magnetic material. Subsequently, the surface of the sputtered non-magnetic material is dry etched, thereby the projecting end surfaces of the convex portions constituting the servo pattern, the recording tracks, and the like (surfaces of the magnetic material) are exposed from the non-magnetic material. With this operation, the magnetic disk is completed.